Production of thioethers of the anthraquinone series



Patented May 19, 1931 omrsnfs*'rA- Es PATENT; OFFICE;

ARTHUR. LumTRInenAUs, or MANNI-IEIM, Lnnwre ,EIFFLAENDER, or .LunwIes- I HAFEN-ON-THE-RHINE, AND FILIP'KAOER, OF MANNHEIM, GERMANY, ASSIGNORS T GENERAL AN'ILINE WORKS, 'INC., OF NEW YORK, N. Y., A CORPORATION OF DELA- v WARE frnonuo'rion orfrnronrn'nns on THE ANTHRAQUINONE snmns No Drawing. Application filed October 27,.1927,- Ser ia1 No. 229,262, and in, Germany October 30, 1926. I

series. I

We have found thatthio-ethersof the anj thraquinone series can be produced by the action of aromaticdiaz o-compounds on anthra quinone-mercaptanes, or the derivatives or substitution products of the said mercaptanes. Thio-ethers of the anthraquinone series are also obtained by-the action of mercaptanes of any desired nature or the derivatives and substitution products thereof on diazo-compounds] of anthraquinones; The strongly mineral acid solutions of the diaZo-anthraquinones, such as are obtainable according to the usual method of diazotizing amino-anthraquinones, may be directly employed. As a rule excellent yields of the thio-ethers of the anthraquinon-e series are thereby obtained. The reaction is of particular importance for the production of 1-thioarylanthraquinone-Q- carboxylic acids, which are important for industrial purposes, as initial materials for the production of the anthraquinone-thioxanthones.

The following examples will further illus trate how this invention may be carried out in practice, though it must be understood that the invention is not limited thereto. The parts are by weight.

Example 1 155 parts of anthraquinone-lethiocyanate- 2-carboxylic acid, obtainable from l-diazoanthraquinone-2-carboxylic acid byheating with potassium thiocyanate and water, are suspended in 3000 parts of water. 300 parts of caustic soda solutions of 40 Baum are added and the mixture is heated to C. whereupon 5000 parts of cold water are added to the bluish-red solution, the temperature falling to 35 C. A diazo solution, prepared as follows is thereupon poured into this solution: parts of 2.5-dichlor-1-aminobenzene are melted and poured into a boiling mixture of 500 parts of water and 260 parts of concentrated hydrochloric acid; this mixture is cooled, and 220 parts of ice are mixed therewith; a solution of 35 parts of sodium nitrite in 120 parts of Water is now run into this violet vat golden-yellow shades.

mixture as rapidly as possible, care being taken that the temperature does not rise to above 5 C. I I

After the addition of the diazonium compound, the mixture is heated for solongto a temperature of 40 0., until no more nitrogen is evolved. The reaction product is thereupon precipitated bythe addition of an acid. By recrystallizing from nitrobenzene the anthraquinone-l thio 2C5 dichlorophe nyl-2-carboxylic acidis obtained in the form of golden-yellow needles having the melting point 298 C. By heating with concentrated sulfuric acid to from to C., the prodnot is converted into the corresponding thioxanthrone, which dyes cotton from a bluish- The dyestuff. is preferably treated for purification with dilute boiling sodium hypochlorite lution; r r Achlormethoxyphenylthio-anthraquinone carboxylic acid is obtained in an analogous manner'from the, diazo-compound of 4-chlor 2-amino-1-methoxybenzene. The said thiocompound gives a dyestufi by ring-formation,

'which dyes cotton reddish-brown from a bluish-violet vat. From the diazo-compound of m-chloraniline a m-chlorphenylthio-am thraquinone-carboxylic acid is obtainedin an analogous manner, which can be converted into an orange colored vat dyestufl. 2-diazoanthraquinone yields a 1.2-dianthraquin onylsulfi'd-Q-carboxylic acid, from which a yellow vat dyestuif can be obtained.

Example 2 A solution of anthraquinone-l.2-isoxazol in sulfuric acid is prepared from 25 .parts of 1-nitro-2-methyl-anthraquinone in accord ance'with Example 1 of the? U. S. Patent 4, 1,417,875 .and the said isoxazol converted in the same solution into l-diazo-anthraquinone-2-carboxylic acid. accordingzto the process described in Example 1 of the U. S. Patent 1,700,790. r

25 parts of sodium anthraquinone-Q-mer J.

captide dissolved in'500- parts of water are stirred into this still strongly. sulfuricacid solution at ordinary temperature. A yellow precipitate of 1.2-dianthraquinonylsulfid-2 lizing sodiumsalt is also very suitable for Ewample 3 18 parts of 2.5-dichlor-l-mercaptobenzene are dissolved in parts of water and 30 parts of caustic soda solution of 30 Baum and stirred at room temperature into a strongly sulfuric acid solution of l-diazoanthraquinone-Z-carboxylic acid obtainable from 25 parts 0t 1-nitro 2-methylanthraq'uinone according to Example 2. A yellow precipitate of anthraquinone-1-thio-2.5 dichlorphenyI-Q-carboxylic acid is thus obtained with evolution of nitrogen. The mixture is broughtto the boil, filtered by suction, and the precipitate washed with water and dried. In order to obtain the carboxylic acid entirely pure, the crude product may be boiled up 7 with water and magnesia, the insoluble impurities being then filtered off, and the pure product precipitated from the yellow solution of the magnesium salt by the addition of hydrochloric acid. The readily crystalthe purification of the acid.

If instead of 2.5-dichlormercaptobenzene other mercaptanes are employed, for example butyl mercaptane or thio-glycolic acid, the corresponding thio-ethers are obtained, for example anthraquinone-l-thiobutyl-2-carboxvlic acid or anthraquinone-l -thioglycolic acid-2-carboxylic acid.

Example 4 11.9 parts of 1.5-diaminoanthraquinone are dissolved at room temperature in- 120 parts of sulfuric acid of 66 Bauni strength and 40 parts of nitrosylsulfuric acid, containing about 13 per cent of nitrous acid, are added to this 7 solution; The whole is thoroughly mixed and then stirred into crushed ice. The diazo-sulfate which separates out, is filtered off by suction and stirred into about 300 parts of water. A solution of 13 parts of p-thiocresol in 50 parts of caustic soda solution of 40 Baum strength and 500 parts of water is stirred into this suspension. After standing for some time, the mixture is brought to boiling, filtered by suction, the precipitate washed,until the wash-water shows neutral reaction, and thereupon dried. The product thus obtained is 1.5-di-p-tolylthio-anthraquir)1one (see Liebigs Annalen, VOl. 393, page 184 i What we claim is:

1. The process of producing anthraquinone-1-thiochlorophenyl 2-carboxyli i acids, which consists in acting on a l-diazoanthra in acting on a 1-diazo-anthraquinone-2-carboxy'lic acid with an aromatic mercaptan,

and heating the reaction mixture until no 1 more nitrogen isevolved.

4. The process of producing anthraquinone-EZ-carboxy-l-thioethers which com-prises acting on. an anthraqhdnone-Q-carboxylic acid with anaromatic compound, one of the said T components containing a mercapto', the other a diazo group, the anthraquinOne-Q carbox yli'c acid containing one of the said groups in the l-position.

In testimony whereof we have hereunto set our hands.

ARTHUR- LUTTRINGHAUS. LUDWIG EIFFLAENDE R. FILIP KACER. 

